When the entire galaxy finds itself under attack from the Deindum — a highly advanced but aggressive and paranoid race from the future — Bernice Summerfield and her various friends and colleagues are scattered across space, doing what they can for the war effort.

Bernice makes her way home before heading back into history, searching for knowledge about their adversary and (hopefully) a weapon which might help the cause. Braxiatel, leading a coalition of civilised worlds against the attack, has cause to question his methods. An exhausted Bev runs the Braxiatel Collection as a refugee centre, fearful of an imminent attack. Adrian and Doggles must overcome their shared history and work together, whilst Hass embarks on a dangerous journey through the galaxy's war zones to the heart of the Deindum's new empire.

But will it be enough? What can they do against one of the most daunting enemies that they have ever faced?